Real-time observation of nanoscale topological transitions in epitaxial PbTe/CdTe heterostructures

H. Groiss, I. Daruka, K. Koike, M. Yano, G. Hesser, G. Springholz, N. Zakharov, P. Werner

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The almost completely immiscible PbTe/CdTe heterostructure has recently become a prototype system for self-organized quantum dot formation based on solid-state phase separation. Here, we study by real-time transmission electron microscopy the topological transformations of two-dimensional PbTe-epilayers into, first, a quasi-one-dimensional percolation network and subsequently into zero-dimensional quantum dots. Finally, the dot size distribution coarsens by Ostwald ripening. The whole transformation sequence occurs during all stages in the fully coherent solid state by bulk diffusion. A model based on the numerical solution of the Cahn-Hilliard equation reproduces all relevant morphological and dynamic aspects of the experiments, demonstrating that this standard continuum approach applies to coherent solids down to nanometer dimensions. As the Cahn-Hilliard equation does not depend on atomistic details, the observed morphological transformations are general features of the model. To confirm the topological nature of the observed shape transitions, we developed a parameter-free geometric model. This, together with the Cahn-Hilliard approach, is in qualitative agreement with the experiments.

Original languageEnglish
Article number012105
JournalAPL Materials
Volume2
Issue number1
DOIs
Publication statusPublished - 2014

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Heterojunctions
Semiconductor quantum dots
Ostwald ripening
Epilayers
Phase separation
Experiments
Transmission electron microscopy

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)

Cite this

Groiss, H., Daruka, I., Koike, K., Yano, M., Hesser, G., Springholz, G., ... Werner, P. (2014). Real-time observation of nanoscale topological transitions in epitaxial PbTe/CdTe heterostructures. APL Materials, 2(1), [012105]. https://doi.org/10.1063/1.4859775

Real-time observation of nanoscale topological transitions in epitaxial PbTe/CdTe heterostructures. / Groiss, H.; Daruka, I.; Koike, K.; Yano, M.; Hesser, G.; Springholz, G.; Zakharov, N.; Werner, P.

In: APL Materials, Vol. 2, No. 1, 012105, 2014.

Research output: Contribution to journalArticle

Groiss, H, Daruka, I, Koike, K, Yano, M, Hesser, G, Springholz, G, Zakharov, N & Werner, P 2014, 'Real-time observation of nanoscale topological transitions in epitaxial PbTe/CdTe heterostructures', APL Materials, vol. 2, no. 1, 012105. https://doi.org/10.1063/1.4859775
Groiss, H. ; Daruka, I. ; Koike, K. ; Yano, M. ; Hesser, G. ; Springholz, G. ; Zakharov, N. ; Werner, P. / Real-time observation of nanoscale topological transitions in epitaxial PbTe/CdTe heterostructures. In: APL Materials. 2014 ; Vol. 2, No. 1.
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